ML18093B560
| ML18093B560 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 05/12/1988 |
| From: | Tiernan J BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| TASK-2.K.3.05, TASK-TM GL-86-06, GL-86-6, TAC-49674, TAC-49675, NUDOCS 8805200335 | |
| Download: ML18093B560 (4) | |
Text
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BALTIMORE GAS AND ELECTRIC CHARLES CENTER
- P. 0. BOX 1475 *BALTIMORE, MARYLAND 21203 JOSEPH A. TIERNAN VJCE PRESIDENT NUCLEAR ENERGY U. S. Nuclear Regulatory Commission Washington, DC 20555 May 12, 1988 ATTENTION:
Document Control Desk
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit Nos. 1 & 2; Docket Nos. 50-317 & 50-318 Response to Request for Additional Information -
Generic Letter 86-06 (TACS 49674 and 49675)
REFERENCES:
(a) Letter from Mr. S. A. McNeil (NRC) to Mr. J. A. Tiernan (BG&E),
dated February 24, 1988, Request for Additional Information -
Generic Letter 86-06, "Implementation of TMI Action Item 11.K.3.5, Automatic Trip of Reactor Coolant Pumps" Gentlemen:
As requested in Reference (a), we are providing the non-proprietary information used from the CE report, NPSD-151, "CE Safety Analysis Method for Calvert Cliffs Units 1 and 2."
There is no non-proprietary version of the complete report available, therefore, we have extracted the non-proprietary portion of the trending tables that were used in our evaluation.
Should you have any questions on this matter, we will be pleased to discuss them with you.
JA T /PSF /WPM/ dlm cc:
D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC S. A. McNeil, NRC W. T. Russell, NRC D. C. Trimble, NRC 88os200335 e:::os:t~
PPDR ADOCK 05000317 DCD
TABLE 8-1 KEY INPUT P/\\llAMETERS Atm TllE IR IMPACT ON TllE LOSS OF LOAD EVENT Par;meter Sense of Chanqe Power Level lligher
\\
lligher RCS Pressure Lower Physical Impact 1.. /\\ higher initial power level ~1ill initiate the event from conditions closer to SAFDLs.
i
- 2. /\\higher power will maximize the power to pressurizer steam space ratio.
A bighe~ Tinlet will initiate*
the event from conditions closer to SAFOLs.
- 1. A lower initial pressure will initiate the event from conditions closer to SAFDLs.
- 2.
A lower initial pressure delays the time of high pressurizer pressure trip and thus maximizes the.rate of pressure change at time of trip.
*- *---~
... =*=~-=*
"~--*-=-*=**-~~--~.. *--*-------------*--*---**-*--.
Impact on Analytical Results
- 1.
No impact on transient results ex-cept that higher powers lower the initial ONBR and thus result in a lower transient minimum ONBR.
l
- 2.
/\\ higher power to steam space ratio will maximize the peak pressure during the event.
No impact on transient results except that a higher Tinlet lowers the initial DNBR and thus results in a *lower tran-sient minimum ONBR.
- 1.
No impact on minimum ONBR during the event since no credit is taken for the pressure increase.
- 2.
Lower initial pressure delays time of trip. This maxi~izes the rate of change of pressure at time of trip and t~~s res~]ts in higher peak RCS pressures~
co I
\\.0
Par;*r.1eter
- 1 MTC Doppler Coefficient Sense of Change More Positive (i.e., BOC)
Less Negative (i.e., BOC)
Mi~her I
TABLE B-1 (continued)
Phys1cal Impact A more positive MTC in combina-tion with increasing coolant tempera tu res wi 11 add greater positive reactivity. This in-creases the core power, heat flux, coolant system pressure and temperatures.
A less negative Doppler coe'fficient in combination with increasing fuel temperatures, adds less negative reactivity ThiS maximizes the increase in power, heat flux, coolant Ii temperature and pressure.
Allows the heat flux to follow the power more closely. Also, ilicreases the rate at \\'1hich the heat generated within the fuel gets into the coolant and there-by increases the coolant tempera lures and l~CS pressure.
Impact on Analyt1cal Results
- 1.
Increasing core average heat flux and coolant temperature result in lower. transient orrnn values.
- 2.
Maximizes the peak RCS pressure during the event.
- 1.
- 2.
Results in higher core heat flux and coolant temperatures and thus minimizes the transient DNBR.
Maximizes the peak RCS pressure.
- 1. Results in higher core average heat flux and coo 1 ant tempera tu res and thus minimizes the transient ONBR.
- 2.
Maximizes the peak RCS pressure.
~
I......
0 i
Parm1eter Initial Steam Generator Pressure Axial Power Distribution Sense of Chanqe Lower Top Peaked Sera~
Positive neactivity Insertion Curve (i.e. 1 ASI)
Pressurizer Pressure Control System Inoperable (i.e.,
no sprays or PROVs)
T/\\OLE 8-1 (continued}
Physical Impact A lower initial steam generator pressure delays the time when main steam safety valves open.
The delay in opening the MSSVs increases the heatup of both the primary and secondary systems.
A top peaked shape results in higher enthalpy rise in the hot channel.
Scram reactivity insertion associated with a positive ASI 1 minimizes the scram reactivity inserted after a reactor trip. This maxi-rni zes the power, heat flux, coolant temperature and pressure overshoot.
More pronounced transient *
- variations in primary pressure.
Impact on Analytical Results Maximizes the peak RCS pressure.
- l. Maximizes core average heat flux, and coolant temperatures.
- 2.
Maximizes RCS pressure.
Maximizes peak RCS pressure.
\\
0 0 *
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